[pulseaudio-discuss] Does pulseaudio resample when source and sink sample rate / bits are identical?

Colin Guthrie gmane at colin.guthr.ie
Sun Jul 17 04:30:25 PDT 2011

'Twas brillig, and Joshua Redstone at 17/07/11 00:35 did gyre and gimble:
> Hi Colin,
> Thanks, yeah 'pacmd list-sink-inputs' confirms that no resampling is
> happening.
> One other question:  I presume that a sink volume setting for of 100%
> means no attentuation or amplification is happening, correct?

Correct. Even if some volume adjustment is happening, in many
circumstances we won't actually do this in software anyway... this is a
feature known as "flat volumes". If only one stream is playing and the
stream volume is 50% while the sink volume is 100%, we'll actually just
adjust the underlying alsa kcontrols to 50% as this is the only thing
playing... provided you don't actually look at the underlying kcontrols
everything works as efficiently as possible. Of course sometimes
hardware attenuation/gain isn't accurate enough for us (as it tends to
be in quite large chunks at times) so we have to "top up" the adjustment
in software.



Colin Guthrie

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